Permeable pavement and cured carbon fiber composition and a related method

ABSTRACT

A permeable pavement and cured fiber composition and a related method are provided. The permeable pavement composition includes a quantity of pavement material, and a quantity of cured carbon fiber composite material (CCFCM) configured to be added to the pavement material to produce a reinforced composition having improved characteristics. An example of pavement material includes a pervious concrete material. The method includes providing a quantity of pavement material, and adding a quantity of cured carbon fiber composite material to the pavement material to produce a reinforced composition having improved characteristics.

TECHNOLOGICAL FIELD

The present disclosure relates generally to reinforced permeablepavement compositions. More particularly, the present disclosure relatesto a permeable pavement and cured carbon fiber composition and a relatedmethod for enhanced mechanical reinforcement and durability.

BACKGROUND

Pervious concrete (PC) is one pavement out of the suite of permeablepavements (e.g., asphalt, concrete, stone/gravel, clay, etc.) thatsimultaneously serves storm water runoff management and supportsvehicular or pedestrian traffic. PC is growing in popularity amongmunicipalities and transportation agencies for applications such as bikelanes, pedestrian walkways, sidewalks, parking lots, low-volume roadwaysand others.

The increased application is mainly due to PC's environmental benefits,such as underground water system restoration and storm water runoffreduction. When used as a pavement surface course, PC may mitigatetraffic noise and potentially reduce the heat island effect.

However, when compared to some traditional pavement materials (e.g.,Portland cement concrete (PCC)), PC lacks strength capabilities. This isbecause PC essentially eliminates fine aggregates in its composition andincludes a gap or open gradation of coarse aggregate, which facilitatesthe flow of water. Further, due to the lack of fine aggregate, thecoarse aggregate grains in PC are bounded solely by a thin layer ofcement paste, which results in lower mechanical properties of PC ascompared to traditional PCC, where coarse aggregate is embedded in thematrix. Typical values of 28-day compressive strength for PC range fromabout 2.8 MPa to about 28 MPa as opposed to about 20 MPa to about 40 MPafor traditional PCC. Accordingly, it would be desirable for a permeablepavement (e.g., pervious concrete) to have improved characteristics thatsimultaneously provide environmental benefits (e.g., underground watersystem restoration and storm water runoff reduction), while maintainingthe compressive strength of traditional pavement materials.

BRIEF SUMMARY

Example implementations of the present disclosure are directed to apermeable pavement and cured carbon fiber composition and a relatedmethod. Example implementations provide a reinforced permeable pavementcomposition having improved characteristics in terms of durability,wear, workability during placement, and variability as compared withother non-reinforced permeable pavement materials and/or othertraditional pavement materials.

The present disclosure provides a permeable pavement compositioncomprising a quantity of pavement material and a quantity of curedcarbon fiber composite material (CCFCM) configured to be added to thepavement material to produce a reinforced composition having improvedcharacteristics.

In some other aspects, the present disclosure provides a method ofmaking a permeable pavement composition comprising: providing a quantityof pavement material; and adding a quantity of cured carbon fibercomposite material (CCFCM) to the pavement material to produce areinforced composition having improved characteristics.

The features, functions and advantages discussed herein may be achievedindependently in various example implementations or may be combined inyet other example implementations further details of which may be seenwith reference to the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWING(S)

Having thus described example implementations of the disclosure ingeneral terms, reference will now be made to the accompanying drawings,which are not necessarily drawn to scale, and wherein:

FIG. 1 illustrates an exemplary graphical representation of a particlesize distribution of elements of cured carbon fiber composite material(CCFCM) according to some aspects of the present disclosure;

FIG. 2 illustrates four different particle size elements of CCFCM:C-combined, L-large, S-small, and M-medium according to some aspects ofthe present disclosure;

FIG. 3 illustrates an exemplary graphical representation of an averageporosity based on specimen type, where the number of specimens includesseven small cylinders, five large cylinders and one slab per compositionaccording to some aspects of the present disclosure;

FIG. 4 illustrates an exemplary graphical representation of acorrelation between porosity and density for small cylinders accordingto some aspects of the present disclosure;

FIG. 5 illustrates an exemplary graphical representation of an averageinfiltration rate based on a specimen type according to some aspects ofthe present disclosure;

FIG. 6 illustrates an exemplary graphical representation of an averagecompressive strength (ƒ′_(c)) on 7- and 28-day test normalized byporosity according to some aspects of the present disclosure;

FIG. 7 illustrates an exemplary graphical representation of anoccurrence of different failure types on (top) 7- and (bottom) 28-dayƒ′_(c), tests according to some aspects of the present disclosure;

FIG. 8 illustrates an exemplary graphical representation of averagetensile strength for 7-day tests according to some aspects of thepresent disclosure;

FIG. 9 illustrates an exemplary graphical representation of an average28-day elastic modulus for all mixtures according to some aspects of thepresent disclosure;

FIG. 10 illustrates a progression of degradation during Cantabro testwith number of cycles provided in bottom right corner, and illustratesin the right photograph an experimental setup for the surface abrasiontest according to some aspects of the present disclosure;

FIG. 11 illustrates all slab specimens after the surface abrasion testwas conducted according to some aspects of the present disclosure;

FIG. 12 illustrates an exemplary graphical representation of an averagemass loss by (left) Cantabro and (right) surface abrasion according tosome aspects of the present disclosure;

FIG. 13 illustrates an exemplary graphical representation ofinfiltration rates of exemplary asphalt compositions according to someaspects of the present disclosure;

FIG. 14 illustrates an exemplary graphical representation of tensilestrength values for exemplary asphalt compositions calculated from anindirect tensile test procedure according to some aspects of the presentdisclosure;

FIG. 15 illustrates an exemplary graphical representation of a ruttingdepth performance for exemplary asphalt compositions as obtained throughthe Hamburg Wheel Track test method according to some aspects of thepresent disclosure; and

FIG. 16 illustrates a method flow diagram for a method for making apermeable pavement composition comprising a pavement material and acured carbon fiber composite material according to some aspects of thepresent disclosure.

DETAILED DESCRIPTION

Some implementations of the present disclosure will now be describedmore fully hereinafter with reference to the accompanying drawings, inwhich some, but not all implementations of the disclosure are shown.Indeed, various implementations of the disclosure may be embodied inmany different forms and should not be construed as limited to theimplementations set forth herein; rather, these example implementationsare provided so that this disclosure will be thorough and complete, andwill fully convey the scope of the disclosure to those skilled in theart. For example, unless otherwise indicated, reference something asbeing a first, second or the like should not be construed to imply aparticular order. Also, something may be described as being abovesomething else (unless otherwise indicated) may instead be below, andvice versa; and similarly, something described as being to the left ofsomething else may instead be to the right, and vice versa. Likereference numerals refer to like elements throughout.

Example implementations of the present disclosure are generally directedto a permeable pavement material and cured carbon fiber compositionmaterial (CCFCM) and a related method. In some exemplaryimplementations, the present disclosure provides a reinforced perviousconcrete composition having improved physical properties, improvedchemical compositions, improved functional performances, and the like(i.e., “improved characteristics”), when compared to traditionalconcrete materials or non-reinforced pervious concrete materials. Inother aspects, the present disclosure provides a reinforced porousasphalt composition having improved characteristics when compared totraditional asphalt materials or non-reinforced porous asphaltmaterials.

More particularly, the improved characteristics comprise, for example,an increased or maintained split tensile strength, an improved ormaintained modulus of elasticity, improved or maintained abrasionresistance, increased ductility, improved or maintained fatigue crackingresistance, improved or maintained low temperature cracking, and/orimproved or maintained rutting resistance. Alternatively, or in additionto those described above, the improved characteristics can furthercomprise, for example, a maintained or decreased porosity, an increasedor maintained filtration rate, and/or an increased or maintainedcompressive strength. The improved characteristics can also comprise areduction in toxicity, such that the reinforced compositions disclosedherein are substantially non-toxic to aquatic and/or semi-aquatic lifeand aid in the mitigation of storm water pollutants. Such exemplaryimproved characteristics allow the reinforced compositions to beutilized in multiple applications, such as, transportation applications(e.g., bike lanes, pedestrian walkways, sidewalks, parking lots,roadways and others, etc.), as well as any other application wherepavement compositions are typically utilized.

The pavement material is, in some aspects, any type of traditionalpavement material such as concrete, asphalt, clay, gravel, etc. As notedherein, the terms “pervious”, “permeable”, “porous”, and the like aresynonymous when referenced with the term “pavement material” or“pavement.” The type of pavement material used in the composition isdependent on the pavement application.

An exemplary pavement material comprises pervious concrete (PC). PC isprepared, in some exemplary implementations, as a mixture comprised ofcement, water, admixtures, and coarse aggregate. In some aspects, littleto substantially no fine aggregate is included in the PC mixture. Oneexemplary PC mixture comprises a Type I/II ordinary Portland CementConcrete (PCC) and saturated surface dry (SSD) crushed basalt coarseaggregate incorporated therewith and having a nominal maximum size of ⅜inches, a specific gravity of about 3.102, and about 3.11 percent waterabsorption.

In some mixtures, a certain percentage of the cement is replaced withsecondary cementitious materials such as fly ash, slag, silica fume, andothers. For example, about 15 percent of the cement by mass is replacedwith Type F fly ash, although this percentage is variable between about10 percent and about 40 percent of the cement by mass. Water tocementitious ratio (w/cm) is achievable at, for example, about 0.24.However, the water to cementitious ratio is modifiable according to thePC mixture. In some aspects, a rheology-modifying chemical admixture isused to delay the setting of the PC mixture, providing more workabilitytime. For example, approximately 583.0 ml of admixture are used.Additionally, the PC mixture is designed following a mixture designprocedure. For example, a PC mixture is designed following the mixturedesign procedure available in ACI 522-R-10, using a target porosity ofabout 27 percent (i.e., about 27 percent air voids).

Accordingly, exemplary ranges for a reinforced composition including PCare provided below in TABLE 1, where ranges in proportioning of thepavement material and the CCFCM are clearly set forth. In one exemplaryaspect, a quantity of CCFCM added to the PC mixture is about 0.5 percentto about 5.0 percent CCFCM by volume of the reinforced PC composition.

TABLE 1 Material Amount per m³ of PC Mixture SSD Coarse aggregate [kg]1000-4000 Fine aggregate [kg]  0.0-200 Water [kg]  50-150 Cement [kg]150-320 Fly ash [%] 10-40% replacement of cement within PC mixtureAdmixture [ml] As needed CCFCM [kg] 0.0-100.0 (0.0-6.0 percent volumePC)

Another exemplary pavement material comprises porous asphalt (PA). Aswith PC, PA is prepared using the same methods as traditional asphaltbut little to substantially no fine aggregate is included in the PAmixture. PA is prepared, in some exemplary implementations, as a mixturecomprised of binder and an aggregate, which is incorporated with aquantity of CCFCM to produce a reinforced PA composition. The aggregatecomprises, for example, particles or elements such as stone, sand,gravel, and the like, while the binder mixture comprises, for example, acrude oil blend, a nonpetroleum blend, and the like. In some aspects,the PA mixture is prepared from about a 95% aggregate and a 5% bindermixture incorporated with about a three percent, about a six percent, orabout a nine percent CCFCM per total weight of the asphalt binder. Thesevalues correspond to 0.15 percent CCFCM, about 0.30 percent CCFCM, orabout 0.45 percent CCFCM per total weight of the reinforced PAcomposition. Other percentages of the binder mixture to CCFCM dosage arealso contemplated depending on the use application of the reinforced PAcomposition.

A quantity of the CCFCM is added to the pavement material to produce areinforced composition having improved characteristics. In someinstances, the quantity of the CCFCM added is dependent on the quantityof the pavement material added (and vice versa), as well as variouscharacteristics of the pavement material and the CCFCM.

One or more components of the CCFCM comprise, in some aspects,polyacrylonitrile (PAN)-type carbon fiber or similar fiber and a bindingpolymer or matrix material such as a thermoplastic resin, e.g., an epoxyresin. In some other aspects, some of the one or more components of theCCFCM are recycled materials (e.g., waste synthetic fibers, waste carbonfiber composites (CFCs), and the like embedded in a matrix material),which may include undesirably large particle size fractions.

Accordingly, one or more components of the CCFCM may require furtherprocessing and/or refinement to separate the components of the CCFCMinto different particle size fractions. The CCFCM is, in some exemplaryaspects, processed and/or refined in any manner of ways. As disclosedherein, the processing and/or refining methods advantageously includelow-energy methods that preserve the characteristics of the wastematerial components of the CCFCM. By contrast, known recycling or reusemethods are known to process and/or refine the waste material componentsin such a manner that is environmentally hazardous, inefficient, and/orexpensive (e.g., a chemical solvent or burn processing method).

Initially, where one or more of the components of the CCFCM comprises awaste fiber material, it is desirable to separate elements of thesecomponents by reducing the size, removing cured resins etc., in a mannerthat is not costly and is environmentally preferred, i.e., is not achemical and/or thermal process. As such, the elements of the CCFCM areseparated by mechanical deconstruction such as shredding, hammering,milling, sieving, etc. In some aspects, the elements of the CCFCM areseparated by first shredding and then refined using a mechanicalrefinement mechanism (e.g., a hammer-mill) through, for example, a25.4-mm screen to separate out the coarsest particles.

In another example, the elements of the CCFCM are further separated intodifferent particle size fractions relative to a weight by volumepercentage of the composition in order to achieve properly gradedclasses of CCFCM for incorporation in PC or PA. Such properly gradedclasses of CCFCM advantageously, in some aspects, are able to maintainrequired infiltration rates, yet maintain or have improved workabilityand mechanical properties.

In one instance, the elements of the CCFCM are differentiated into fourdifferent particle size fractions, though fewer or greater groupings arealso contemplated, by further mechanical screening. FIG. 1 illustratessuch an instance of four different particle size fractions, whichinclude: (C) combined: particles smaller than about 3.35 mm, (L) large:particles smaller than about 3.35 mm and larger than about 2.00 mm, (M)medium: particles smaller than about 2.00 mm and larger than about 0.841mm, and (S) small: particles smaller than about 0.841 mm (retained onthe pan). In another instance, FIG. 2 illustrates four differentparticle size fractions. As seen in FIG. 2, coarse and flaky CCFCMparticles are contained in C and L, while S and M mainly containedparticles in the form of fibers. These broadly graded classes wereselected to experiment with different shapes and graded classes of CCFCMin improving the properties of PC and PA in one exemplary study.However, other combinations of graded classes and shapes are able to beused depending on processing methods, pavement designs, and/or requiredproperties.

Consequently, the compositions and related methods, as disclosed hereinprovide a secondary use for an increasing waste stream of fibermaterials, specifically CFCs. Expenses traditionally associated withchemical and thermal treatments to isolate elements of the waste streamof fiber materials have proven to be prohibitive. As described herein,low-energy intensive repurposing strategies advantageously recycle awaste fiber material, while allowing the waste fiber material to retainmuch of its original properties and to be easily dispersed into manyother materials, including pavement materials.

EXAMPLE 1

An experiment was designed to investigate the effect of different CCFCMelement volume fractions, as well as different particle size fractionsof the elements of the CCFCM relative to a weight by volume percentageof a PC composition on the characteristics of the composition itself.Therefore, experimental samples or specimens of various compositionsincluding a PC pavement material were prepared, the experimental samplesincluding: one control concrete composition, three reinforced PC (rPC)compositions containing three volume fractions of a same size fractionand four rPC compositions containing four different size fractions ofthe processed CCFCM. The seven mixtures and their designated namingsystem are provided below in TABLE 2.

For each mixture, the first letter represents the CCFCM element particlesize fraction, (C, L, M, and S) followed by a number that represents theCCFCM element volume fraction in percentage, 0.5, 1.0, and 1.5 percent,respectively. In the case of the control composition, the letter and thenumber that describe the CCFCM element size and volume fraction werereplaced with 00.

TABLE 2 CCFCM Content CCFCM [% volume of the Mixture ID Element Sizeexperimental sample] Control 00 Not Applicable Not Applicable C0.5Combined 0.5 C1 Combined 1 C1.5 Combined 1.5 S1.5 Small 1.5 M1.5 Medium1.5 L1.5 Large 1.5

The PC was mixed in accordance with the ASTM C192. Prior to mixing,elements of the CCFCM and the admixture were dispersed in the totalwater for the batch. Three types of specimens were cast for thisexperiment: small cylindrical specimens (about 100 mm in diameter byabout 200 mm in height), prepared for 7- and 28-day compressive strengthand Cantabro tests, large cylindrical specimens (about 150 mm indiameter by about 300 mm in height) for a 7-day split tensile strengthtest, and slabs (about 28.6 mm in length by about 28.6 mm in width byabout 8.3 mm in height) for mass loss in surface abrasion tests. Duringthe mixing it was observed that elements of the CCFCM dispersed evenlyand without clumping throughout the fresh PC material.

A compaction method for the cylinders was selected to result inuniformly compacted specimens for strength testing, while the slabs werecompacted to represent field placement and compaction procedure. Aquantity of the composition placed in each specimen mold waspredetermined according to the designed density. Small and largecylindrical samples were filled with a determined quantity of thecomposition in two and three lifts, respectively. Lower lifts werecompacted with about 15 blows and about 20 blows of a standard Proctorhammer for small and large cylinders, respectively, where the hammer wasa 5.5 pound hammer falling about 12 inches. The final lift was placed byfilling the mold to the top and compacting with the needed number ofProctor hammer blows to fit the predetermined weight of the compositionin the mold. Slab molds were filled with fresh PC in one lift andcompacted with about 33 blows of the standard

Proctor hammer. Subsequently slabs were compacted using a hydrauliccompression testing machine, applying the load of about 3.1 kN,corresponding to a Bunyan roller compaction used for compacting PC inthe field. To make sure the compositions filled the mold consistently,the molds were hit with a plastic mallet on the side all around eachspecimen about five times per lift for small cylinders and 10 times perlift for large cylinders and slabs.

All specimens were cured in closed (capped) molds for seven days in thelaboratory conditions, with ambient temperature maintained at about 21degrees Celsius.

Upon demolding the specimens at 7-day age, hardened porosity and drydensity were determined in accordance with ASTM C1754. Air void contentwas estimated as the difference between the total volume of the specimenand the volume of the displaced water when the specimen was submerged,using EQUATION 1.

$\begin{matrix}{{{Void}\mspace{14mu} {content}} = \left\lbrack {1 - \frac{M_{w} - M_{d}}{\rho_{w}*V}} \right\rbrack} & {{EQUATION}\mspace{14mu} 1}\end{matrix}$

where M_(w) is the mass of submerged specimen, M_(d) is the mass of dryspecimen, ρ_(w) is density of water, and V is volume of the specimen,estimated based on the average dimensions obtained from threemeasurements taken using a caliper. As such, in some examples, thespecimen comprised an air void content or porosity of about 15 percentto about 35 percent air voids, and more particularly about 18 percent toabout 28 percent air voids, which is a porosity level sufficient for thespecimens to be considered a “pervious” pavement material.

FIG. 3 illustrates the average porosity in a three data series,representing small cylinders, large cylinders, and slabs. As evident inFIG. 3, all the rPC compositions presented lower average porosities(about 22 percent to about 24 percent air voids) when compared to thecontrol PC composition (about 28 percent air voids). It was also evidentfrom the standard deviation (whisker bars in FIG. 3) that the rPCspecimens from the same composition were compacted significantly moreconsistently than the control specimens.

To establish the significance of the effect of the CCFCM elements on rPCporosity, Pearson t-tests were conducted on small cylinders from eachcomposition and the control composition. The test results show that thedifference in porosity of rPC compositions and control composition wasstatistically significant at about a 95 percent confidence interval(p-value is zero for each rPC composition when compared to the controlcomposition). From a practical point of view, the significantly lowerporosity achieved for rPC compositions with the same compaction effortimplies that the addition of the CCFCM elements to the PC compositionsincreases the mixture's workability. This is advantageous consideringthe low slump and workability of PC, especially when placing in thefield in hot weather conditions.

Dry density was estimated for each specimen. The correlation betweenporosity and dry density for small cylindrical specimens from allcompositions is presented in FIG. 4. As illustrated in FIG. 4, rPCcompositions showed a linear relationship between porosity and drydensity (R²=0.97), while porosity of the control composition showed adisparity in relatively small range of density. The relativelyconsistent density for the control samples despite the clear change inporosity was most likely due to variability in the volume of thespecimens. The linear correlation between density and porosity for therPC specimens demonstrated again that the CCFCM elements resulted inhigher workability and therefore uniform volumes among all rPCspecimens.

Infiltration rate is one of the properties of PC that is desirable forstorm water management applications. Therefore, the infiltration rate ofthe PC specimens was determined based on the procedure outlined in ASTMC1701 at 7-day age. Cylindrical specimens were wrapped on the sides withshrink-wrap, which enabled the water to be poured from the top andexfiltrated through the bottom of the specimens without loss on thesides. Infiltration rate of the slab specimens was determined by theusage of a plastic infiltration ring, fastened to the slab by theplumber's putty. An infiltration rate for the slabs was reported as theaverage of the measurements from four different locations on each slab.Infiltration rates (I) were determined based on EQUATION 2:

$\begin{matrix}{I = \frac{4\; V}{D^{2}\pi \; t}} & {{EQUATION}\mspace{14mu} 2}\end{matrix}$

where, V is volume of infiltrated water, D is the diameter of thespecimen in case of cylindrical specimens and the diameter of theinfiltration ring in the case of slab specimens and t is the timerequired for the measured volume of water to infiltrate through thecomposition. Accordingly, one exemplary increased infiltration rate wasreported at about 200 inches per hour to about 3,000 inches per hour.

FIG. 5 illustrates the infiltration rates for each specimen category. Asseen in FIG. 5, rPC specimens generally presented higher infiltrationrates than the control specimen. The increase in infiltration ratesranged from about 4 percent to about 32 percent for small cylinders,from about 14 percent to about 55 percent for large cylinders, and fromabout 11 percent to about 96 percent for slabs. As such, the variabilityin the increase in infiltration rates was attributable, at least inpart, to a geometry, a cross-sectional area, a size, a shape, and thelike of the specimens.

Also, referring back to FIG. 3, rPC specimens presented lower porositycompared to the control composition. Consequently, despite the lowerporosity for the rPC specimens, the higher infiltration rates evidencedthe elements of the CCFCM influencing the connectivity of the air voidsand facilitating the flow of water through the air voids. It should benoted that the average values of infiltration for all the cylindricalspecimens were well within the typical range for PC, i.e., about 750cm/h to about 5,000 cm/h.

As illustrated in FIG. 5, out of the different specimen categories, theslabs presented the highest infiltration rates for all the specimentypes. High values for the infiltration of the slabs were caused by theplacing methodology (one lift for the slabs as opposed to two and threelifts for small and large cylinders, respectively) and the lowercompaction energy in comparison with the cylindrical specimens.

Additionally, as illustrated in FIG. 5, CCFCM dosage did not present asignificant influence on the average infiltration rate in the case ofcylindrical specimens, while the infiltration of the slabs was thelowest at mid-range CCFCM content. When different CCFCM types werecompared, it was noted that S and L fractions were associated withhigher values of infiltration in the case of the slabs and smallcylinders. The infiltration rate of large cylinders was relativelyconsistent for all rPC specimens containing about 1.5 percent CCFCM.

A compressive strength (ƒ′_(c)) test was performed on small cylindricalspecimens at 7- and 28-day ages, according to ASTM C39. TABLE 3 showsthe average 7- and 28-day ƒ′_(c) results with corresponding standarddeviations for all experimental specimens. Furthermore, a Pearsonstatistical t-test for two samples at a 95 percent confidence intervalwas conducted to determine whether the mechanical properties of rPC andcontrol specimens differed significantly. P-values were reported inTABLE 3.

TABLE 3 Test/Mixture Control C0.5 C1 C1.5 S1.5 M1.5 L1.5 Average 7-dayf′_(c) [MPa] 15.5 14.0 16.6 11.0 9.5 12.0 12.4 St. dev. [MPa] 1.2 2.71.5 2.5 4.7 2.7 1.9 p-value — 0.388 0.287 0.03 0.092 0.082 0.053 Average28-day f′_(c) 19.5 21.2 21.6 20.6 16.0 20.2 21.4 St. dev. [MPa] 3.4 4.41.9 1.8 3.7 2.1 2.8 p-value — 0.550 0.360 0.585 0.222 0.713 0.422Average 7-day f′_(t) [MPa] 1.8 2.0 1.8 2.6 2.2 2.6 2.2 St. dev. [MPa]0.4 0.3 0.2 0.2 0.2 0.3 0.3 p-value — 0.434 0.96 0.02 0.108 0.016 0.146Average Ec [MPa] 21.9 31.7 29.6 24.5 31.0 23.4 32.1 St. dev. [MPa] 4.810.1 3.5 2.1 6.3 5.6 10.6 p-value — 0.603 0.898 0.229 0.380 0.344 0.495

Consequently, TABLE 3 illustrates that only rPC specimens C1outperformed the control specimens in terms of 7-day ƒ′_(c). Conversely,on 28-day tests, five out of the six rPC specimens presented higherƒ′_(c) than the control specimens (by about 4 percent to about 11percent). The specimen with the lowest ƒ′_(c), on both 7- and 28-daytests was S1.5. Overall, although no significant increase was gained inaverage 28-day ƒ′_(c), compared to the control specimens, the average28-day ƒ′_(c), for all the rPC specimens was greater than about 20 MPa,which is a typical value for PC materials. As such, in one instance, theincreased or maintained compressive strength is about 5 MPa to about 30

MPa.

When evaluating ƒ′_(c), test results for PC materials, porosity is aninfluential characteristic. Specimens with higher porosity generallypresent lower strengths. To consider the effect of porosity on theƒ′_(c), test results, FIG. 6 illustrates the 7- and 28-day ƒ′_(c),results for each specimen normalized by their corresponding porosity.FIG. 6 isolates the potential effect of porosity on the tests results tofocus solely on the effect of CCFCM addition. The increase in 28-dayƒ′_(c), for almost all rPC specimens with reference to the controlspecimens is evident in FIG. 6. When different CCFCM dosages werecompared, it was observed that C1 yields the highest ƒ′_(c), on bothtest days. When different CCFCM types were compared, it was observedthat the coarser CCFCM element particle size fractions generallyresulted in higher 28-day ƒ′_(c).

When gains in ƒ′_(c), from 7- and 28-day were compared, it was observedthat all rPC specimens, except C1, underwent more significant increasein ƒ′_(c), than the control specimen. This behavior shows that the CCFCMelements were likely to have hindered or slowed down the hydrationprogress. All of the rPC specimens with about 1.5 percent CCFCM had f ,gains higher than about 60 percent, which was substantially higher thanthat of the control specimens (about 26 percent).

To further examine the effect of CCFCM on ƒ′_(c), the failure modes inall specimens were investigated. Eight major failure types areidentified for the 7- and 28-day compressive strength tests and arepresented with descriptions in TABLE 4. These failure types aredescribed based on ASTM C39 for conventional PCC. Additionally, threefrequently observed failure types: bottom-up, and top-down columnarcracking, and cone with shear, were added to those defined in ASTM C39.

TABLE 4 Columnar cracks Failure Bottom-up (BU) Top-down (TD) withpartially type name columnar cracks columnar cracks formed cones ConeFailure type Not Available NA Type 3 Type 1 from ASTM (NA) C39Description Columnar cracks Columnar cracks Columnar crackingWell-formed cones propagate from the propagate from the from both endswith on both ends, caps bottom upwards top downwards partially formedintact after failure. evenly around. evenly around. cones at one end.Failure type Shear Crushing of top or Cone and shear Side fractures namebottom Failure type Type 4 Type 6 NA Type 5 from ASTM C39 DescriptionDiagonal fracture Severe cracking at Well-formed cone at Side fracturesat throughout, without top/bottom, one end, prominent top/bottom;cracking on resulting in diagonal (shear) resembles shear top/bottom.crushing of cracks on another. failure, with cracks top/bottom. on thetop/ bottom.

FIG. 7 illustrates the occurrence of the different failure types on 7-and 28-day tests, respectively. Six different failure types can beobserved in FIG. 7 for the 7-day test. Columnar cracking (TD and BU) andcolumnar cracking with partially formed cones are relatively frequentfailure types. Crushing of top or bottom of the specimen is anotherrecurrent failure type, typically associated with low ƒ′_(c). Shear andside cracking are less frequent failure types on 7-day ƒ′_(c), tests.

As illustrated in FIG. 7, on 28-day ƒ′_(c), testing, specimens presentedfour different failure types. The most common failure type was shear,followed by the combination of cone and shear. Specimens with highest28-day ƒ′_(c), demonstrated cone failure type, while the specimens withlower 28-day ƒ′_(c), typically failed by side cracking. Based on theresults in FIGS. 6 and 7, it was concluded that strength gains of PCspecimens were associated with changes in structural integrity,resulting in change of prevalent failure types.

An indirect split tensile strength (ƒ′_(t)) test was performed accordingto ASTM C496 on four large cylindrical specimens at 7-day age. Theaverage 7- day ƒ′_(t) for all PC specimens with their correspondingstandard deviations is presented in TABLE 3. Similar to ƒ′_(t) , testresults, a Pearson statistical t-test at a 95 percent confidenceinterval was performed on test results and p-values are listed in TABLE3.

As seen in TABLE 3, five out of the six rPC specimens outperformed thecontrol specimens in terms of 7-day ƒ′_(t) of the PC by about 11 percentto about 46 percent. The increase in ƒ′_(t) was statisticallysignificant for the specimens C1.5 and M1.5. The seven-day ƒ′_(t) ofspecimens C1 was slightly lower (about three percent) than that of thecontrol specimen, which is not statistically significant. All of thespecimens with about 1.5 percent CCFCM presented relatively high valuesof ƒ′_(t), beyond about 2.2 MPa. Overall, the average 7-day ƒ′_(t) forall rPC specimens was about 2 MPa, which is about 26 percent higher thanthat of the control specimen at about 1.8 MPa. As TABLE 3 illustrates,most 7-day ƒ′_(t) values for rPC specimens exceeded the typical rangefor PC reported in other studies (from about 1.4 MPa to about 2 MPa).

Similar to ƒ′_(c), porosity influenced ƒ′_(t) of the PC specimens. Toisolate the effect of porosity on 7-day ƒ′_(t), the test result for eachspecimen was normalized to its corresponding porosity in FIG. 8. As seenin FIG. 8, all rPC specimens outperformed the control specimen in termsof 7-day ƒ′_(t) after the normalization. When different CCFCM dosageswere compared, it was noted that about 1.5 percent of CCFCM elementsresulted in the highest value of ƒ′_(t) normalized by porosity. Whendifferent CCFCM element particle size types were compared, it wasconcluded that combined and medium CFC element particle size fractionsyielded the highest value of ƒ′_(t) normalized by porosity. In terms offailure types, it was observed that the experimental specimens thatpresented higher strength generally had full split failures and loweroccurrence of failures at the lift locations.

Load-displacement measurements during testing were available for the28-day ƒ′_(c) tests. The modulus of elasticity (E_(c)) was estimated asthe slope of the linear trend-line used to approximate the linearportion of stress-strain curves. Initial stresses (up to about 0.35 MPa)were considered as the seating period.

The average E_(c) with the corresponding standard deviation for everymixture is given in TABLE 3. As compressive and tensile strength testresults, the Pearson's statistical tests were conducted on the values ofE_(c) and corresponding p-values are provided in the TABLE 3. As seen inTABLE 3, four out of six rPC specimens outperformed the control specimenin terms of E_(c) (by about 4 percent to about 46 percent). SpecimensC1.5 and M1.5 presented lower average E_(c) than the control specimen,while the specimen L1.5 showed the highest E_(c), about 32 MPa onaverage. FIG. 9 illustrates that the E_(c) values were normalized by thecorresponding porosities. When different CCFCM dosages were compared, itwas noted that higher dosages yielded lower E_(c) normalized toporosity. However, when different CCFCM particle sizes were compared, itwas noted that small and large CCFCM fractions at about 1.5 percentvolumetric dosage resulted in relatively high values of E_(c) normalizedto porosity.

A Cantabro test was performed according to ASTM C1747 on four smallcylindrical specimens per mixture, obtained by cutting the regular 100mm by 200 mm cylinders in half. Specimens were tested on Cantabro about50 days after casting. The test was conducted in a Los Angeles (LA)abrasion test machine without the steel ball charges. FIG. 10 shows thedegradation of one rPC experimental specimen after every 50 cycles inthe LA abrasion machine.

Abrasion tests with the rotational cutter were performed according toASTM C944, with about a 98 N load on the slabs. The test was performedat four different locations on each slab, for a total time of about 14minutes per each location. The experimental setup for the surfaceabrasion test is illustrated in FIG. 10. FIG. 11 illustrates all theslab specimens after the surface abrasion test was conducted, where theset-up slab was used to set up the machine.

FIG. 12 illustrates the average mass loss from Cantabro and surfaceabrasion test for all PC specimens. Specimen M1.5 was the only rPCspecimen that outperformed the control specimen in terms of average massloss on the Cantabro test. Specimen L1.5 had the highest average massloss on the Cantabro test, about 40 percent after 500 cycles. SpecimenC0.5 presented lower mass loss on the surface abrasion test than thecontrol composition. Mass loss of specimens C1.5 and M1.5 was very closeto that of the control specimen. Specimen L1.5 presented the highestmass loss on the abrasion test (about 0.66 percent on average), whilethe average mass loss of the control specimen was about 0.2 percent.Relatively high abrasion resistance of the specimen M1.5 corresponded toits relatively high resistance during the Cantabro test, as well as itsrelatively high 7-day tensile strength. The specimen L1.5 wascharacterized with the highest mass losses on both tests. Specimens C0.5and C1.5 demonstrated high abrasion resistance, followed with mid-rangemass losses on Cantabro. Specimens C1, S1.5 and L1.5 were characterizedwith relatively low abrasion resistance at both abrasion and Cantabrotests.

In order to determine which mechanical properties (7-day ƒ′_(c), 28-dayƒ′_(c) , and E_(c)) best corresponded to the resistance to degradation,based on the Cantabro test, and surface abrasion, Pearson correlationfactors with corresponding p-values were calculated and presented inTABLE 5.

TABLE 5 Control C0.5 C1 C1.5 S1.5 M1.5 L1.5 Cantabro 28-day f′_(c,)−0.799 0.916 0.649 0.927 NA 0.524 0.384 p-value 0.201 0.084 0.351 0.073NA 0.476 0.616 7-day f′_(t) 0.21 0.967 0.49 0.508 NA −0.419 0.035p-value 0.79 0.033 0.51 0.492 NA 0.419 0.035 E_(c) −0.308 0.875 0.3610.696 NA 0.211 0.119 p-value 0.692 0.125 0.639 0.304 NA 0.789 0.881Surface 28-day f′_(c,) −0.153 −0.554 0.441 −0.904 0.890 −0.197 0.898abrasion p-value 0.847 0.446 0.559 0.096 0.11 0.803 0.102 7-day f′_(t)−0.353 −0.285 −0.553 −0.455 −0.821 −0.058 0.392 p-value 0.647 0.7150.447 0.545 0.179 0.942 0.608 E_(c) −0.769 −0.768 0.753 −0.224 0.8040.517 −0.518 p-value 0.231 0.232 0.247 0.776 0.196 0.483 0.482

As seen in TABLE 5, resistance to degradation based on the Cantabro testcorrelated relatively well with 28-day ƒ′_(c), and 7-day ƒ′_(c), in thecase of specimens with a combined CCFCM fraction. In the case ofspecimen C0.5, resistance to degradation correlated well with all threeexamined mechanical parameters. For specimens M1.5, L1.5 and the controlspecimen, significant linear correlation between the degradationresistance and mechanical properties was not established. A strongcorrelation between the surface abrasion resistance and mechanicalproperties was not defined. Moreover, as TABLE 5 shows, most correlationfactors were negative, which indicated that higher mechanical propertieswere associated with lower performance on the surface abrasion test.However, it was noted that losses on surface abrasion tests wererelatively low (below about 0.6 percent) and the values of the remainingmass percentage were dispersed around a very small range.

Consequently, the experimental study described herein was designed andexecuted in order to investigate the ease and feasibility of mixing PCmaterial with CCFCM. The use of CCFCM with the PC material resulted inimproved characteristics of the reinforced PC specimens includingsignificantly improved workability associated with lower and moreconsistent porosity compared to the control specimen. Increasedworkability desirably eased the placement, finishing, and/or compactionin real-world applications, and provided more time for placementespecially during extreme working conditions. Despite the lowerporosity, the infiltration rates were desirably increased in the samespecimen. Other improved characteristics included higher gains in ƒ′_(c)compared to the control specimen, which indicated that CCFCM desirablyinfluenced the hydration process. Additionally, the improvedcharacteristics of the reinforced specimens further included, anincreased ƒ′_(t) an increased E_(c), high resistance to degradation, andhigh resistance to surface abrasion as compared to the control specimen.

EXAMPLE 2

An experiment was designed to investigate the effect of adding differentquantities of CCFCM to a porous asphalt (PA) material. The results ofthe testing determined that the addition of the CCFCM resulted in thereinforced PA (rPA) compositions having improved characteristics.Therefore, experimental samples or specimens of various compositionsinclude one control composition, four rPA compositions containing avolume size fraction of a same size and different size fractions of theprocessed CCFCM, and four rPA compositions containing a volume sizefraction of a same size and different size fractions of the processedCCFCM.

In some aspects, compared with the experimental rPC specimens in EXAMPLE1, four of the rPA specimens included a higher load of CCFCM (i.e., 3percent by weight). As with the rPC specimens, the infiltration rates ofthe rPA also improved with some CCFCM dosages as the porosities remainedsimilar. The mechanical structure of the rPA specimens were alsogenerally improved relative to the control specimen. Using the indirecttensile test procedures on the fabricated cylinders, all rPA specimensexhibited increased tensile performance, with those specimens includinga high percentage and larger size CCFCM (e.g., specimen 3L) providingthe most benefit to the tensile strength as seen in FIG. 14.Accordingly, the increased or maintained split tensile strengthcorresponds to an addition of about three percent of carbon fibershaving a particle size smaller than about 3.35 mm and larger than about2.00 mm to the quantity of the pavement material, such that theincreased or maintained split tensile strength, in one instance, isabout 0.5 MPa to about 5 MPa.

A rutting test was also performed to assess the wear performance of thespecimens. As FIG. 15 illustrates, the rPA specimens showed a reductionin rut depth with the addition of CCFCM to the PA material. Thisincrease in performance was also seen in the Cantabro test where areduction in the weight loss was found with the rPA specimens.

Consequently, the experimental study described herein was designed andexecuted in order to investigate the ease and feasibility of mixing PAmaterial with CCFCM. The use of CCFCM with the PA material resulted inimproved characteristics of the reinforced PA composition includingincreased tensile strength, increased infiltration rates, and/orreduction in rut depth.

Referring now to FIG. 16, an exemplary method generally referred to as100, is provided. The method 100 includes a method for making apermeable pavement composition, such as that referred to herein. In afirst step, 102, a quantity of pavement material is provided. Thepavement material is, in some aspects, PA or PC.

In a second step, 104, a quantity of cured carbon fiber compositematerial CCFCM is added to the pavement material to produce a reinforcedcomposition having improved characteristics.

Adding the quantity of CCFCM comprises adding the quantity of CCFCMcomprising carbon fibers incorporated with a binding polymer.

Prior to step 104, elements of the CCFCM are separated from the CCFCM bymechanical deconstruction using, for example, a mechanical refinementmechanism.

The elements of the CCFCM are further separated into different particlesize fractions relative to a weight by volume percentage of thecomposition.

Adding the quantity of CCFCM to the pavement material to produce thereinforced composition having improved characteristics comprisesproducing a reinforced composition having a porosity of about 15 percentto about 35 percent air voids.

In some aspects, adding the quantity of CCFCM to the pavement materialto produce the reinforced composition having improved characteristicscomprises producing a reinforced composition having a maintained ordecreased porosity, an increased or maintained infiltration rate, anincreased or maintained split tensile strength, an increased ormaintained compressive strength, an improved or maintained modulus ofelasticity, an improved or maintained abrasion resistance, increasedductility, improved or maintained fatigue cracking resistance, improvedor maintained low temperature cracking, or improved or maintainedrutting resistance.

The reinforced composition can be utilized in transportationapplications (e.g., bike lanes, pedestrian walkways, sidewalks, parkinglots, roadways and others, etc.)

Many modifications and other implementations of the disclosure set forthherein will come to mind to one skilled in the art to which thedisclosure pertains having the benefit of the teachings presented in theforegoing description and the associated drawings. Therefore, it is tobe understood that the disclosure is not to be limited to the specificimplementations disclosed and that modifications and otherimplementations are intended to be included within the scope of theappended claims. Moreover, although the foregoing description and theassociated drawings describe example implementations in the context ofcertain example combinations of elements and/or functions, it should beappreciated that different combinations of elements and/or functions maybe provided by alternative implementations without departing from thescope of the appended claims. In this regard, for example, differentcombinations of elements and/or functions than those explicitlydescribed above are also contemplated as may be set forth in some of theappended claims. Although specific terms are employed herein, they areused in a generic and descriptive sense only and not for purposes oflimitation.

What is claimed is:
 1. A permeable pavement composition comprising: aquantity of pavement material; and a quantity of cured carbon fibercomposite material (CCFCM) configured to be added to the pavementmaterial to produce a reinforced composition having improvedcharacteristics.
 2. The permeable pavement composition according toclaim 1, wherein the CCFCM comprises carbon fibers incorporated with abinding polymer.
 3. The permeable pavement composition according toclaim 1, wherein elements of the CCFCM are configured to be separated bymechanical deconstruction.
 4. The permeable pavement compositionaccording to claim 3, wherein elements of the CCFCM are configured to beseparated by a mechanical refinement mechanism.
 5. The permeablepavement composition according to claim 4, wherein the mechanicalrefinement mechanism comprises a hammer-mill.
 6. The permeable pavementcomposition according to claim 3, wherein the elements of the CCFCM areconfigured to be further separated into different particle sizefractions relative to a weight by volume percentage of the composition.7. The permeable pavement composition according to claim 6, wherein theparticle size fractions comprise: particles smaller than 3.35 mm,particles smaller than 3.35 mm and larger than 2 mm, particles smallerthan 2 mm and larger than 0.841 mm, and particles smaller than 0.841 mm.8. The permeable pavement composition according to claim 1, wherein thepavement material is a pervious concrete.
 9. The permeable pavementcomposition according to claim 1, wherein the reinforced compositioncomprises a hardened porosity of about 15 percent to about 35 percentair voids.
 10. The permeable pavement composition according to claim 1,wherein the improved characteristics comprise at least one of amaintained or decreased porosity, an increased or maintainedinfiltration rate, an increased or maintained split tensile strength, anincreased or maintained compressive strength, an improved or maintainedmodulus of elasticity, improved or maintained abrasion resistance,increased ductility, improved or maintained fatigue cracking resistance,improved or maintained low temperature cracking, and improved ormaintained rutting resistance.
 11. The permeable pavement compositionaccording to claim 10, wherein the increased infiltration rate comprisesan infiltration rate of about 200 inches per hour to about 3,000 inchesper hour.
 12. The permeable pavement composition according to claim 10,wherein the increased or maintained compressive strength is about 5 MPato about 30 MPa.
 13. The permeable pavement composition according toclaim 10, wherein the increased or maintained split tensile strength isabout 0.5 MPa to about 5 MPa.
 14. The permeable pavement compositionaccording to claim 1, wherein the reinforced composition is utilized intransportation applications.
 15. A method of making a permeable pavementcomposition comprising: providing a quantity of pavement material; andadding a quantity of cured carbon fiber composite material (CCFCM) tothe pavement material to produce a reinforced composition havingimproved characteristics.
 16. The method according to claim 15, whereinadding the quantity of CCFCM comprises adding the quantity of CCFCMcomprising carbon fibers incorporated with a binding polymer.
 17. Themethod according to claim 15, comprising, prior to adding the quantityof the CCFCM to the pavement material, separating elements of the CCFCMby mechanical deconstruction.
 18. The method according to claim 17,wherein separating the elements of the CCFCM by mechanicaldeconstruction comprises separating the elements of the CCFCM using amechanical refinement mechanism.
 19. The method according to claim 17,comprising further separating the elements of the CCFCM into differentparticle size fractions relative to a weight by volume percentage of thecomposition.
 20. The method according to claim 15, wherein providing thequantity of pavement material comprises providing a quantity of perviousconcrete.